Crash in ParticleField.onDraw about leonids HOT 3 CLOSED

Thanks for the heads up. Surprisingly enough I have never seen this crash myself, but by looking at the stack trace and your explanation I must have just been lucky.

How do you manage to replicate it? It may be dependant on the Android version.

from leonids.

No problem. It's a great library and really saved me some time apart from this small issue. My test device is running 4.4.2. I'm creating the ParticleSystem like so...

mParticles = new ParticleSystem((Activity)getContext(), 100, R.drawable.particle, 5000)
    .setSpeedRange(0.0f, 0.1f)
    .setScaleRange(0.1f, 0.9f)
    .setFadeOut(1000)
    .setParentViewGroup((ViewGroup) findViewById(R.id.particle_view));
mParticles.emit(0, 0, 10);

In my parent view's onSizeChanged function I do the following to ensure the particles emit from the center on the view...

@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    super.onSizeChanged(w, h, oldw, oldh);
    mParticles.updateEmitPoint(w / 2, h / 2);
}

I'm also running some other animations within the parent view which cause frequent invalidates. All I have to do to see the crash is sit and let it run. Sometimes it happens immediately, sometimes it takes a couple minutes. It seems to happen a bit faster if I change the orientation (landscape<>portrait) of the device a few times to cause the view to resize & invalidate.

I quickly worked around it by adding a synchronized(mActiveParticles) {} block in ParticleSystem.onUpdate, and a synchronized (mParticles) {} in ParticleField.onDraw. No more crashes.

from leonids.

It could be that on rotation some particles are "lost" but definitely, I'm
going to add the synchronized part.

Thanks for the heads up!

On Fri, 24 Apr 2015 6:13 pm kibantony [email protected] wrote:

No problem. It's a great library and really saved me some time apart from
this small issue. My test device is running 4.4.2. I'm creating the
ParticleSystem like so...

mParticles = new ParticleSystem((Activity)getContext(), 100, R.drawable.particle, 5000)
.setSpeedRange(0.0f, 0.1f)
.setScaleRange(0.1f, 0.9f)
.setFadeOut(1000)
.setParentViewGroup((ViewGroup) findViewById(R.id.particle_view));
mParticles.emit(0, 0, 10);

In my parent view's onSizeChanged function I do the following to ensure
the particles emit from the center on the view...

@OverRide
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mParticles.updateEmitPoint(w / 2, h / 2);
}

I'm also running some other animations within the parent view which cause
frequent invalidates. All I have to do to see the crash is sit and let it
run. Sometimes it happens immediately, sometimes it takes a couple minutes.
It seems to happen a bit faster if I change the orientation
(landscape<>portrait) of the device a few times to cause the view to resize
& invalidate.

I quickly worked around it by adding a synchronized(mActiveParticles) {}
block in ParticleSystem.onUpdate, and a synchronized (mParticles) {} in
ParticleField.onDraw. No more crashes.

—
Reply to this email directly or view it on GitHub
#19 (comment).

from leonids.